Security scanner with bin return device

ABSTRACT

A security screening system for scanning items, the system comprising: a scanner, configured to produce x-ray projection data as an object is passed through the scanner, at least a portion of the scanner being received within a structure, the structure having an input opening and an outlet opening, the input opening being configured to receive objects to be scanned and the output opening being configured to receive objects scanned by the scanner; an input conveyor for passing a plurality of bins through the input opening to the outlet opening, the input conveyor having an input end for receiving the plurality of bins to pass the plurality of bins into the input opening and an output end for delivering the plurality of bins from the outlet opening; and a return conveyor positioned to return the plurality of bins to an area proximate to the input end of the input conveyor, the return conveyor being positioned below the input conveyor, wherein the return conveyor does not pass through the scanner.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of U.S. patent applicationSer. No. 11/298,925 filed Dec. 9, 2005, the contents of which areincorporated herein by reference thereto.

BACKGROUND

This present invention relates generally to an apparatus and method forscanning and inspecting baggage. More particularly, the presentinvention relates to security screening systems for use at airports orother areas (e.g., court houses, buildings, arenas, seaports, hospitals,corporate facilities, government buildings, mailrooms, correctionalfacilities, nuclear power stations, special events, public areas, etc.)wherein a secure area is required.

In airport applications carry-on baggage inspection systems generallyutilize a scan projection (SP) image for presentation to the operator.In most baggage inspection systems, scan projection images are createdby moving an object under a fan beam of x-rays from a stationary x-raysource.

In some computed tomography (CT) imaging system configurations, an x-raysource projects a fan-shaped beam which is collimated to lie within anX-Y plane of a Cartesian coordinate system and generally referred to asan “imaging plane”. The x-ray beam passes through an object beingimaged. The beam, after being attenuated by the object, impinges upon anarray of radiation detectors. The intensity of the attenuated radiationbeam received at the detector array is dependent upon the attenuation ofthe x-ray beam by the object. Each detector element of the arrayproduces a separate electrical signal that is a measurement of the beamintensity at each detector location. The intensity measurements from allthe detectors are acquired separately to produce a transmission profile.

In third generation CT systems, the x-ray source and the detector arrayare rotated with a gantry within the imaging plane and around the objectto be imaged such that the angle at which the x-ray beam intersects theobject constantly changes. A group of x-ray attenuation measurements(e.g., projection data), from the detector array at one gantry angle isreferred to as a “view”. A “scan” of the object comprises a set of viewsmade at different gantry angles, or view angles, during one revolutionof the x-ray source and detector about the object or patient beingimaged.

To perform a “helical” scan, the object is continually moved via aconveyor belt while the projection data for the prescribed number ofslices is acquired. The helix mapped out by the fan beam yieldsprojection data from which images in each prescribed slice may bereconstructed. Orthographic and scan projection SP-like images can becreated from helical scan data by reconstruction of the entire volume,and projecting digitally through the reconstructed volume.

During the scanning of the object, potentially harmful X-ray beams areshielded by the structure of apparatus surrounding the conveyor belt andshielding means disposed at the apparatus entry and exit points (e.g.,curtains disposed on the entry and exit points). In order to provide thenecessary shielding an x-ray blocking material (e.g., lead, aluminum,carbon fibers or any other material that inhibits X-rays) is disposed inthe apparatus structure and the curtains disposed at the entry and exitpoints.

However, these curtains may obstruct the flow of baggage on the conveyoras they may cause lighter objects (e.g., smaller bags, purses, carry onluggage, etc.) to tumble or even stop on the conveyor. This isexacerbated if such a device were to be used as an initial securityscreening measure at airport check in as typically smaller objects,purses, coats, shoes, laptops must be placed on the conveyor for x-rayscreening.

In addition, these security devices are typically located proximate topersonal screening devices wherein individuals desiring to be clearedthrough a security screening must place all of their belongings, metalobjects, shoes, electronic devices etc. into a bin or tub designed totravel through the screening device. Thereafter, the individual walksthough a personal screening device (e.g., metal detector) for clearanceinto the secure area.

Typically, these bins or tubs are located on an input side of a conveyorfor the screening device and are left on the output side after theobjects have been screened and picked up by their owner who has alsocleared the security screening by passing through the personal screeningdevice. Typically, the security screening location is set up as abarrier wherein entrance into the secure area is limited to accesspoints wherein objects and personal must be screened or cleared prior toentry into the secure area. Therefore, once an individual is clearedthrough the personal screening they are free to retrieve their personalbelongings as the output side of the security screening device. Thus andonce their belongings are retrieved, the empty bins are left at theoutput side until an authorized security screening person picks up theempty bins and walks through the personal screening device back to theinput side of the security screening device.

During this process of returning the empty bins to the input side of thesecurity screening device, the personal security device is disabled orno longer usable for personal screening as one of the security personalmust hand carry the empty bins to the input side. As might be expectedthis will slow the screening process of individuals wishing to enter thesecure area as well as require manpower from the security personnel.Moreover, and in airports large bottlenecks may occur as passengers arecleared through the security checkpoint. Thus, any disruption to thisprocess will exacerbate the bottleneck or slow down the securityclearance.

Accordingly, it is desirable to provide an apparatus and method forreturning empty bins used in a security screening process that does notadversely affect the security screening process. In addition, it is alsodesirable to provide an x-ray shielding means that does not interferewith the throughput of objects through the scanning system.

SUMMARY OF THE INVENTION

An apparatus and method for providing a means for returning empty binsto an input side of a security screening device or system.

In one exemplary embodiment, a security screening system for scanningitems is provided. The system comprising: a scanner, configured toproduce x-ray projection data as an object is passed through thescanner, at least a portion of the scanner being received within astructure, the structure having an input opening and an outlet opening,the input opening being configured to receive objects to be scanned andthe output opening being configured to receive objects scanned by thescanner; an input conveyor for passing a plurality of bins through theinput opening to the outlet opening, the input conveyor having an inputend for receiving the plurality of bins to pass the plurality of binsinto the input opening and an output end for delivering the plurality ofbins from the outlet opening; and a return conveyor positioned to returnthe plurality of bins to an area proximate to the input end of the inputconveyor, the return conveyor being positioned below the input conveyor,wherein the return conveyor does not pass through the scanner.

In another exemplary embodiment, a security screening system forscanning items is provided. The system comprising: a scanner, configuredto produce x-ray projection data as an object is passed through thescanner, at least a portion of the scanner being received within astructure, the structure having an input opening and an outlet opening,the input opening being configured to receive objects to be scanned andthe output opening being configured to receive objects scanned by thescanner; an input conveyor for passing a plurality of bins through theinput opening to the outlet opening, the input conveyor having an inputend for receiving the plurality of bins to pass the plurality of binsinto the input opening and an output end for delivering the plurality ofbins from the outlet opening; and a return pathway positioned to returnthe plurality of bins to an area proximate to the input end of the inputconveyor, the return pathway being positioned below the input conveyor,wherein the return pathway does not pass through the scanner.

In another exemplary embodiment, a method for returning a plurality ofempty bins used in a security screening process is provided. The methodcomprising: advancing a plurality of bins through a scanner using aninput conveyor, the input conveyor having an input end for receiving theplurality of bins and an output end for delivering the plurality ofbins, the scanner being configured to produce x-ray projection data asan object is passed through the scanner, at least a portion of thescanner being received within a structure, the structure having an inputopening and an outlet opening, the input opening being configured toreceive objects to be scanned and the output opening being configured toreceive objects scanned by the scanner; and returning the plurality ofbins to the input end after they have passed through the scanner with areturn conveyor, the return conveyor being configured to return theplurality of bins to an area proximate to the input end of the inputconveyor, the return conveyor being positioned below the input conveyor,and the return conveyor does not pass through the scanner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are schematic illustrations of a CT scanning system;

FIG. 3 is a perspective view of a CT scanning system in accordance withan exemplary embodiment of the present invention;

FIGS. 4 and 5 are partial perspective views of an exemplary embodimentof the present invention;

FIG. 6 is a top plan view of an exemplary embodiment of the presentinvention;

FIG. 7 is a view along lines 7-7 of FIG. 6;

FIG. 8 is a perspective view of a CT scanning system in accordance withan alternative exemplary embodiment of the present invention;

FIG. 9 is a partial side view of a CT scanning system in accordance withan alternative exemplary embodiment of the present invention;

FIG. 10 is perspective view of a security screening system according toan alternative exemplary embodiment;

FIG. 11 is perspective view of a security screening system according toanother alternative exemplary embodiment; and

FIG. 12 is perspective view of a security screening system according toyet another alternative exemplary embodiment.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The disclosure of the present invention relates to an apparatus andmethod for returning empty bins used in a security screening process,wherein the return of the empty bins does not adversely affect thesecurity screening process. In addition, exemplary embodiment of thepresent invention also relate to an apparatus and method for providing ashielding means for use with x-ray detection systems. In particular, theshielding means is contemplated for use with security checkpoint systemsconfigured to scan luggage, carry on luggage and other items beingloaded onto an airplane.

Accordingly, exemplary embodiments of the present invention are directedto a system for returning bins or tubs configured to hold the items tobe scanned by a screening or scanning device. In addition, otherexemplary embodiments of the present invention are directed to bins ortubs configured to hold the items being scanned while the bin or tubcomprises a portion of the x-ray shielding of the scanning device. Inaddition, exemplary embodiments of the present invention are alsocontemplated to provide a method for determining when an object or tubis in the proper location for scanning and the appropriate shielding isin place. Moreover, additional exemplary embodiments provide methods forincreasing the throughput of the scanning device.

Referring now to FIGS. 1 and 2, a computed tomography (CT) imagingsystem 10 is shown. FIGS. 1 and 2 are intended to provide a non-limitingexample of a CT imaging system. CT imaging system 10 is shown having agantry 12, which is representative of a CT scanner, a control system 14,and a motorized conveyor 16 for positioning an object 18, such as apiece of luggage, in gantry opening 20 in gantry 12. Gantry 12 includesan x-ray source 22 that projects a fan beam of x-rays 24 toward adetector array 26 on the opposite side of gantry 12. Detector array 26is formed by detector elements 28. Detector elements 28 are radiationdetectors that each produces a signal having a magnitude that representsand is dependent on the intensity of the attenuated x-ray beam after ithas passed through object 18 being imaged. During a helical scan thatacquires x-ray projection data, the gantry along with the x-ray sourceand detector array rotate within the imaging plane and around the objectabout a center of rotation 30, while the object is moved through thegantry in a z-direction 32 perpendicular to the imaging plane.

Gantry 12 and x-ray source 22 are controlled by control system 14, whichincludes a gantry controller 36, an x-ray controller 38, a dataacquisition system (DAS) 40, an image reconstructor 42, a conveyorcontroller 44, a computer 46, a mass storage-system 48, an operatorinterface 50, and a display device 52. The gantry controller controlsthe rotational speed and position of the gantry, while the x-raycontroller provides power and timing signals to the x-ray source, andthe data acquisition system acquires analog data from the detectorelements and converts the data to digital form for subsequentprocessing. The image reconstructor receives the digitized x-ray datafrom the data acquisition system and performs an image reconstructionprocess that involves filtering the projection data by using a helicalreconstruction algorithm.

Computer 46 is in operable communication with the gantry controller, thex-ray controller, and the conveyor controller whereby control signalsare sent from the computer to the controllers and information isreceived from the controllers by the computer. The computer alsoprovides commands and operational parameters to the data acquisitionsystem and receives a reconstructed image data from the imagereconstructor. The reconstructed image data is stored by the computer inthe mass storage system for subsequent retrieval. An operator interfaceswith the computer through the operator interface, which may include, forexample, a keyboard and a graphical pointing device, and receivesoutput, such as, for example, a reconstructed image, control settingsand other information, on the display device.

Operable communication between the various system elements of FIG. 2 isdepicted by arrowhead lines, which illustrate a means for either signalcommunication or mechanical operation, depending on the system elementinvolved. Operable communication amongst and between the various systemelements may be obtained through a hardwired or a wireless arrangement.The computer may be a standalone computer or a network computer and mayinclude instructions in a variety of computer languages for use on avariety of computer platforms, such as, for example, DOS-based systems,Apple-based systems, Windows-based systems, UNIX-based systems, or thelike. Other examples of the computer include a system having amicroprocessor, microcontroller or other equivalent processing devicecapable of executing commands of computer readable data or program forexecuting a control algorithm. In order to perform the prescribedfunctions and desired processing, as well as the computations therefore(e.g., the execution of fourier analysis algorithm(s), the controlprocesses prescribed herein, and the like), the controller may include,but not be limited to, a processor(s), computer(s), memory, storage,register(s), timing, interrupt(s), communication interfaces, andinput/output signal interfaces, as well as combinations comprising atleast one of the foregoing. For example, the controller may includeinput signal filtering to enable accurate sampling and conversion oracquisitions of such signals from communications interfaces. Asdescribed above, exemplary embodiments of the present invention can beimplemented through computer-implemented processes and apparatuses forpracticing those processes.

Although a CT scanner is shown and described herein it is alsounderstood that exemplary embodiments of the present invention may beused with other types of x-ray scanning devices wherein shielding andincreased throughput is required and that the present invention is notlimited to CT scanners. Non-limiting examples of such devices includeX-ray scanning devices, line scanning devices, etc.

Referring now to FIG. 3, a perspective view of CT scanning system and anx-ray inhibiting container constructed in accordance with an exemplaryembodiment of the present invention is illustrated. As illustrated, a CTscanning system 70 has a structure 72 configured to receive therein atleast a gantry of a CT scanner, wherein the gantry comprises an x-raysource that projects a fan beam of x-rays toward a detector array on theopposite side of the gantry. As previously discussed, a non-limitingexample of one such gantry and CT scanner is illustrated in FIGS. 1 and2.

As previously discussed, it is desirable to protect the CT scanneroperator and individuals from x-rays generated by the x-ray source.Thus, and in accordance with an exemplary embodiment, structure 72 willcomprise x-ray inhibiting materials in order to provide the desiredx-ray shielding while allowing for x-ray scanning of objects. However,and in order to pass objects through the system, the structure isconfigured to have an input opening 74 and an outlet opening 76, whichare configured to allow objects placed on a motorized conveyor belt 78to pass into opening 74, through a gantry opening 80 for CT scanning andthereafter out outlet opening 76.

One non-limiting contemplated use for system 70 is a luggage or objectscreening means for screening carry on objects of passengers embarkingon airline flights, wherein the carry on luggage or other items arescreened/checked for prohibited items. Accordingly, a passenger wouldplace their objects on the conveyor for scanning by the CT system orother x-ray scanning devices wherein the objects travel into the inputopening and out the outlet opening when the scanning is complete.

Referring now to FIGS. 3-7, and in order to provide a means foreffectively blocking the input and outlet openings of the structure ofthe CT scanning system, a plurality of containers or tubs 82 areprovided. FIGS. 4-7 provide non-limiting illustrations of portions ofstructure 72 with sections removed for clarity. For example, thestructure illustrated in FIGS. 4-7 provides a non-limiting configurationof a portion of structure 72 or may comprise a separate structure withinthe structure 72 of FIG. 3. In other words, the end openings illustratedin FIGS. 4-7 may comprise openings 74 and 76 or alternatively may beadditional openings within structure 72 of FIG. 3.

Nevertheless and in accordance with exemplary embodiments of the presentinvention and in order to protect the CT scanner operator andindividuals from x-rays generated by the x-ray source structure 72 willcomprise x-ray inhibiting materials in order to provide the desiredx-ray shielding while allowing for x-ray scanning of objects and eachtub or container will be configured to locate an x-ray inhibitingmaterial proximate to the input and output openings of the structurehousing the CT scanner or a structure within the structure housing theCT scanner. It is also understood that exemplary embodiments of thepresent invention may be used with other types of x-ray scanning devicesand that the present invention is not limited to CT scanners.

In accordance with an exemplary embodiment each tub or container willcomprise a peripheral wall 84 and a bottom 86, wherein the peripheralwall and the bottom define a receiving area 88. The receiving area 88being configured to receive a plurality of articles 90 therein for CTscanning, non-limiting examples of such articles include lap tops,purses, carry on luggage etc. In addition, each tub or container willcomprise a forward portion 92 and a rearward portion 94, each of whichcomprises a portion of the peripheral wall. In accordance with anexemplary embodiment, forward portion 92 and a rearward portion 94 willalso comprise an x-ray inhibiting material 96 located within orcomprising forward portion 92 and rearward portion 94. In accordancewith an exemplary embodiment the x-ray inhibiting material is lead andin one exemplary embodiment, the x-ray inhibiting material is integrallymolded therein during for example an injection molding of the tub 82.One non-limiting example of a material contemplated for tub 82 is aneasily molded material such as plastic, which will also be lightweightand durable.

In accordance with an exemplary embodiment, the forward portion and therearward portion of each tub is configured to substantially block theinput opening or outlet opening of the structure when positionedproximate thereto. Thus, tubs 82 will provide a means for effectivelyblocking the input and outlet openings and since the forward andrearward portions of the tubs are configured to have an x-ray inhibitingmaterial the tubs will block leakage of spurious x-rays from the CTscanner. In addition, and since tubs 96 will block the openings whendisposed proximate thereto, there no longer is a need to use passivex-ray shielding curtains, which as discussed herein may be draggedinwardly by the item being scanned or the curtains themselves may causesmaller objects to become toppled over or dragged on the conveyor belt.Moreover, such toppled bags or objects may ultimately cause a jam withinthe scanning system, wherein the scanner must be shut down and while theobjects are cleared from their jammed position.

Although the tubs are shown as being rectangular, it is contemplatedthat any configuration of tub is considered to be within exemplaryembodiments of the present invention, as long as each tub comprises aforward and rearward portion configured to substantially block the inputand outlet openings while providing a means for blocking x-rays as thetubs are passed through the CT scanner on a motorized conveyor 98.

In addition, and in accordance with another exemplary embodiment of thepresent invention and in order to determine the location of theplurality of tubs as they are passed through the system, an indicator100 is disposed on a surface of the tub. In accordance with an exemplaryembodiment indicator 100, will comprise machine readable code that isdetectable by a scanning device 102, located on structure 72 in order toscan for and detect indicator 100.

In accordance with an exemplary embodiment the indicator and scannerwill be located to detect a particular location of tub 82 on conveyor 98(e.g., a position wherein either the forward or rearward portion of thetub is located to effectively disposed the x-ray inhibiting material ofthe tub at the inlet or outlet of the structure). One exemplary way ofachieving this is to dispose the indicator in substantially the samelocation on each of the tubs and locate the scanner or its field of viewsuch that once the presence of the indicator is detected it is knownthat the tub will have its forward or rearward portion located in eitherthe inlet or outlet opening. For example, an indicator may be disposedon a surface of the tub six inches away from the rearward portion andthe scanner or its field of view are such that the indicator will not bedetected until a portion of the tub has traveled through the inlet oroutlet opening and the rearward portion is disposed in the correspondingopening (e.g., scanner six inched away from opening). In an alternativeembodiment, and for ease of scanner placement the indicators may belocated equidistant from both the forward portion and the rearwardportion. Non-limiting locations for indicator placement include the tubbottom, side-walls and forward and rearward portions. Moreover,indicator 100 can be used to determine whether a tub without any x-rayshielding is disposed within the structure thus, if the indicator is notdetected no signal is generated to allow the x-ray source to beactivated (e.g., generate x-rays).

In another exemplary embodiment, the forward portion and the rearwardportion of the peripheral wall are each configured to provide apredetermined distance between the receiving area and the x-rayinhibiting material such that an object disposed in the receiving areawill be sufficiently spaced away from the x-ray inhibiting material sothat the x-ray inhibiting material will not interfere with the scanningof the object. A non-limiting example of this configuration is anangular configuration of the forward or rearward portion oralternatively disposing a step portion 105 of non-x-ray inhibitingmaterial in the receiving area. Examples such step portions or angularconfigurations are illustrated by the dashed lines in FIG. 7.

Exemplary embodiments of the present invention also contemplate thex-ray inhibiting container to be configured such that it will also passthrough a gantry opening of a CT scanner as well as the inlet and outletopenings of the structure as it is placed on the motorized conveyor.

In accordance with another exemplary embodiment of the presentinvention, a computed tomography system for scanning items is provided,wherein the system will utilize a plurality of the x-ray inhibitingcontainers along with at least one scanner to detect the presence andlocation of the container as well as provide a signal to a controlsystem of the CT scanning system.

As shown in the Figures, the system will comprise a computed tomographyscanner. The scanner will be configured to produce x-ray projection dataof an object as it is passed through the computed tomography scanner.The system will also comprise structure 72, which defines an internalvolume configured to receive at least the gantry of the computedtomography scanner therein. The structure further comprising inputopening 74 and outlet opening 76, wherein the structure furthercomprises an x-ray shielding material and motorized conveyor 98 forpassing a plurality of tubs 82 through the input opening to the outletopening.

Referring now to FIGS. 3-7, scanning device 102 is positioned to detectindicator 100 and the presence of one of the plurality of tubs. Inaccordance with an exemplary embodiment scanner 102 is positioned todetect container 82 when either the forward portion and or the rearwardportion of the peripheral wall is positioned to substantially cover theinput opening or the outlet opening and the forward portion and therearward portion of each tub comprises an x-ray shielding material.Thus, the location of one of the tubs proximate to scanner 102 such thatindicator 100 is detected will represent a condition wherein the x-rayshielding means of the container is configured to block x-ray leakagefrom the structure.

In an exemplary embodiment, each of the plurality of tubs aresubstantially uniform in size and configuration and location of theindicator on each of the tubs is in substantially the same location suchthat scanner 102 can detect the presence of each tub, wherein thedetected presence will coincide with a tub location wherein either theforward or rearward portion of the tub is in an x-ray blockingconfiguration (e.g., blocking the openings of the structure). Inaddition, each of the plurality of tubs is configured to provide apredetermined distance between the tub volume of each of the pluralityof tubs as they are placed on the motorized conveyor. In other words,the uniform configuration of the tubs will allow for equidistantplacement of objects on the motorized conveyor (e.g., objects placed inthe tubs).

In accordance with an alternative exemplary embodiment, structure 72 isconfigured to have a plurality of partitions 104 located at a distanceabove the motorized conveyor, wherein the distance is such that itallows for un-impeded passage of the plurality of tubs on conveyor 98underneath partition 104. In an exemplary embodiment, partitions 104also comprise an x-ray inhibiting material to provide further x-rayshielding in structure 72. In exemplary embodiments, partitions 104 arein a facing spaced relationship such that the distance between eachpartition substantially aligns with a length of the tubs as they aretraveling along on conveyor 98. For example, as a tub travels alongconveyor 98 there will be a position wherein the forward portion and therearward portion of the tub will align with the partitions. Moreover,scanner 102 or a plurality of scanners 102 (as will be discussed herein)are located to detect the position of each tub as it is substantiallyaligned with the partitions by detecting the presence of the indicatorof one of the tubs.

In accordance with an alternative exemplary embodiment, one of theplurality of partitions 104 is located at either the input end or outletend or both and partition 104 defines a portion or periphery of inlet oroutlet openings.

In accordance with yet another alternative exemplary embodiment, andreferring now to FIG. 8, structure 72 is configured to have a first doormember 110 (illustrated by dashed lines) movably secured proximate tothe input opening for movement between an open door position and aclosed door position, wherein the first door member also comprises anx-ray inhibiting material and is configured to cover the input openingwhen the first door member is in the closed door position. In accordancewith one exemplary embodiment, first door member is placed in the closeddoor position when the last of a plurality of tubs is passed throughinlet opening and x-ray shielding is required (e.g., no more tubs areplaced on the conveyor and as the last tub passes through there is aneed to have shielding at the inlet opening). First door member maycomprise a door member pivotally mounted to the structure by a pluralityof hinges or alternatively a roll up curtain disposed above or besideinlet opening 74. Of course, other door configurations and structuresare contemplated for use in exemplary embodiments of the presentinvention.

In yet another alternative embodiment, and in order to provide a doorclosed signal to a controller of the CT scanning system, a first switchdoor switch 112 is disposed proximate to inlet opening 74, wherein thefirst door switch is configured to provide a door closed signal when thefirst door member is in the closed door position thus, providing asignal indicative that the x-ray inhibiting material of the first doormember is covering the inlet opening. In an exemplary embodiment thissignal is provided to a control algorithm of computer 46, wherein thecomputer will prevent from emitting x-rays unless the door closed signalis received.

Similarly, a second door member 114 (illustrated by dashed lines) inFIG. 8 is movably secured to the outlet opening of the structure formovement between an open door position and a closed door position,wherein the second door member also comprises an x-ray inhibitingmaterial and is configured to cover the outlet opening when the firstdoor member is in the closed door position. In accordance with anexemplary embodiment, second door member is placed in the closed doorposition when the first of a plurality of tubs is passed through inletopening and x-ray shielding is required (e.g., no tubs had beenpreviously placed on the conveyor thus, no shielding or a forward orrearward tubs has been positioned at the outlet opening thus, there is aneed to have shielding at the outlet opening). As with the first doormember, second door member may comprise a door member pivotally mountedto the structure by a plurality of hinges or alternatively a roll upcurtain disposed above or besides outlet opening 76.

In yet another alternative embodiment, and in order to provide a doorclosed signal to a controller of the CT scanning system, a second switchdoor switch 116 is disposed proximate to outlet opening 76, wherein thesecond door switch is configured to provide a door closed signal whenthe second door member is in the closed door position thus, providing asignal indicative that the x-ray inhibiting material of the second doormember is covering the outlet opening. In an exemplary embodiment thissignal is provided to a control algorithm of computer 46, wherein thecomputer will prevent the x-ray source from emitting x-rays unless thedoor closed signal is received. In yet another alternative and whensystem 70 is experiencing low throughput (e.g., small number ofcontainers passing through) the system may be configured to prevent thex-ray source of generating x-rays unless both the closed door signals(inlet and outlet) are received or a combination of one closed doorsignal and the detection of one of the indicator of one of plurality oftubs (e.g., forward or rearward portion of the tubs providing x-rayshielding). In addition, any of the aforementioned embodiments may becombined with the plurality of partitions disposed within the structure.

In yet another alternative exemplary embodiment, the CT scanner will beprovided with a plurality of scanners each being configured and locatedto detect the presence of the indicator of one of the plurality of tubsat a discrete location within the structure, wherein a first one of theplurality of scanners provides a first signal when a first one of theplurality of tubs is located proximate to the input opening and thex-ray shielding material of the first tub is disposed within the inputopening and a second one of the plurality of scanners is located toprovide a second signal when a second one of the plurality of tubs islocated proximate to the opening of the gantry (e.g., in a positionready to be scanned) and a third one of the plurality of scanners ispositioned to provide a third signal when a third one of the pluralityof tubs is disposed proximate to the outlet opening of the structure andthe x-ray shield material of the tub is disposed within the outletopening, wherein the x-ray source is prevented from projecting a fanbeam of x-ray unless the first, the second and the third signals aregenerated.

In other words a plurality of scanners 102 are positioned to generatesignals indicating that the x-ray inhibiting material of the tubs isproximate to the structure opening thus giving an “ok to scan” signal tothe x-ray controller and the conveyor controller (e.g., allowingconveyor to advance while scanning is occurring). Moreover, the secondsignal can be used to indicate that a tub with objects disposed thereinis ready for scanning. Thereafter, the system may be instructed to stopthe conveyor and shut down the x-ray source if another tub is notdetected proximate to the inlet opening or alternatively the outletopening. Moreover, and as discussed above the movable doors and doorclosure switches may be combined with this embodiment to provide methodsfor placing x-ray inhibiting material proximate to the openings of thestructure. Thus, each of these signals may be presented to a controlalgorithm of the system wherein go/no-go signals are provided to atleast the conveyor controller and the x-ray controller as well as thegantry controller. Again, and as in the previous embodiments, thepartitions 104 may be combined with the aforementioned alternativeembodiments. Schematic illustrations of these sensors are provided inFIG. 2, it being understood that any combination of sensors/scanners102, 112 and 116 may be used in exemplary embodiments of the presentinvention.

In yet another alternative exemplary embodiment, and referring now toFIG. 9 and in lieu of scanner(s) 102 and indicator 100, a deflectableswitching member 120 is positioned for movement between an emptyconveyor position 122 and an occupied conveyor position 124. Thedeflectable switching member providing an empty conveyor signal when thedeflectable switching member is in the empty conveyor position, whereinthe x-ray source is prevented from projecting the fan beam of x-ray whenthe empty conveyor signal is generated. The deflectable switching memberbeing configured and positioned to be moved from the empty conveyorposition to the occupied conveyor position by one of the plurality oftubs as it passes through the system on the motorized conveyor. In oneexemplary embodiment, the deflectable switching member comprises adeflectable arm 126 coupled to a micro-switch 128 configured to providea signal as the deflectable arm is moved from the empty conveyorposition to the occupied conveyor position. As illustrated, deflectableswitching member 128 and the plurality of tubs are configured to providethe occupied conveyor signal when the x-ray shielding material of atleast one of the plurality of tubs is located at either the inputopening or the outlet opening of the structure. Moreover, the distalportion of deflectable arm 126 is configured such that it will onlytravel to an unoccupied conveyor position when a container is notproximate to the opening (e.g., distal end is configured such that itcannot drop within the receiving area of the container i.e., width ofdeflectable arm greater than a width of the container).

In yet another alternative exemplary embodiment, deflectable switchingmember 120 may be used in conjunction with any combination ofsensors/scanners 102, 112 and 116 and tubs 82 with indicators 100,wherein deflectable switching member 120 provides a mechanical backup toscanner 102.

Referring now to FIGS. 10-12 another exemplary embodiment of the presentinvention is illustrated. Here a scanning device 210 is shown. Scanningdevice 210 may be a CT scanner or X-ray scanner or any other suitabledevice for screening of objects placed in a bin 282 designed to travelthrough a housing 272 of scanning device 210.

As illustrated scanning device 210 comprises an upper pathway 290supported above a lower pathway 292. In the embodiment illustrated inFIG. 10 upper pathway will comprise a plurality of input rollers 294, aninput conveyor 296 and a plurality of output rollers 298. Asillustrated, and as a bin 282 travels in the direction of arrows 298objects placed in bin 282 will be scanned by scanning device 210.Accordingly, an individual will place their objects in an empty bin atan input side 300 of the scanning device and then proceed through apersonnel screening device 302 wherein and upon clearance through thepersonnel screening device the individual can retrieve their belongingsafter they have been scanned at the output side 304.

In an exemplary embodiment, lower pathway 292 comprises a poweredconveyor 306 configured to return empty bins from the output side to theinput side in a direction of arrows 308. Through the use of lowerpathway 292 and conveyor 306 empty bins are returnable to the input sidewithout requiring an individual to carry the empty bins throughpersonnel screening device 302. Moreover, the individuals who have beencleared may simply place the empty bins on conveyor 306 thus maintaininga steady flow of empty bins to the input side. In addition, and in anexemplary embodiment, the lower pathway or return conveyor passes belowthe scanner and not through it thus, the returning bins do not interferewith the operation of the scanning device. As illustrated, conveyor 306or lower pathway will extend past upper pathway 290 at the input andoutput ends to facilitate ease of transfer of the empty bins to and fromthe lower pathway. Another advantage is that since the lower pathway isdisposed directly below the upper pathway the same will not causescreening device 210 to require a larger footprint or operational area.

In addition, and in order to prevent a backlog or log jam of empty binsa sensor or sensors 310 may be positioned to detect the presence of abin on conveyor 306 at the input side of screening device 210 whereinsensor 310 upon the detection of an empty bin will provide a signal to amotor or motor controller 312 configured to provide a driving force toconveyor 306. Accordingly, and in this embodiment, sensor 310 upon thedetection of an empty bin at input end 300 will provide a stop signal tomotor 312. Thereafter, and once the detected bin is removed a signal isprovide to advance the conveyor 306 in the direction of arrows 308 untilanother empty bin is detected.

In an alternative exemplary embodiment, scanning device 210 isconfigured to be operated with the bins and detection systemsillustrated and described in FIGS. 3-9. Thus, scanning device 210 may beoperated with bins which provide shielding at the input and output endsof the scanning device as well as being operated with an internaldetection system (e.g., scanners positioned to detect indicia on thesides of the bins to determine when the input and output opening of thescanning device are shielded with a portion of the bin.

Referring now to FIG. 11, yet another alternative exemplary embodimentis illustrated. Here, the lower pathway comprises a plurality of rollers314 wherein a portion of the lower pathway is inclined to have adownward slope in the direction of arrows 308. Thus, the empty bins arecapable of being returned to the input side through gravity or a slightpush from the output side. In order to prevent the empty bins fromrolling off the end of the lower pathway at the input end a bumper 318is positioned to stop the empty bins.

In an alternative exemplary embodiment, the scanning device illustratedin FIG. 11 is configured to be operated with the bins and detectionsystems illustrated and described in FIGS. 3-9. Thus, scanning device210 may be operated with bins which provide shielding at the input andoutput ends of the scanning device as well as being operated with aninternal detection system (e.g., scanners positioned to detect indiciaon the sides of the bins to determine when the input and output openingof the scanning device are shielded with a portion of the bin.

Referring now to FIG. 12, yet another alternative exemplary embodimentis illustrated. Here the lower pathway comprises a plurality of rollers314 positioned at the output end wherein the rollers are inclined tohave a downward slop in the direction of arrows 308. In this embodimentrollers 314 traverse completely across a width of the lower pathway. Ofcourse, numerous configurations of rollers 314 are contemplated to bewithin the scope of exemplary embodiments of the present invention.Thereafter, a portion of the lower pathway comprises a powered conveyor306 configured to carry the empty bins received from the roller portionto the input side. In addition, conveyor 306 also comprises an upwardlyinclined portion 316 wherein the empty bins are deposited on an elevatedplatform 318, which is located at the input side of the scanning systemsuch that an individual may easily grasp an empty bin and place is uponrollers 294 for travel in the direction of arrows 298 once the bin isfilled with objects to be scanned.

In addition, and in order to prevent a backlog or log jam of empty binsa sensor or sensors 310 may be positioned to detect the presence of abin on platform 318 wherein sensor 310 upon the detection of an emptybin will provide a signal to a motor or motor controller 312 configuredto provide a driving force to conveyor 306. Accordingly, and in thisembodiment, sensor 310 upon the detection of an empty bin at input end300 will provide a stop signal to motor 312. Thereafter, and once thedetected bin is removed a signal is provide to advance the conveyor 306in the direction of arrows 308 until another empty bin is detected.

Thus, the empty bins are capable of being returned to the input sidethrough gravity or a slight push from the outside and then the motorizedconveyor with deposit the empty bins on platform 318.

In an alternative exemplary embodiment, the scanning device illustratedin FIG. 12 is configured to be operated with the bins and detectionsystems illustrated and described in FIGS. 3-9. Thus, scanning device210 may be operated with bins which provide shielding at the input andoutput ends of the scanning device as well as being operated with aninternal detection system (e.g., scanners positioned to detect indiciaon the sides of the bins to determine when the input and output openingof the scanning device are shielded with a portion of the bin.

While the invention has been described with reference to an exemplaryembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the presentapplication.

1. A security screening system for scanning items, the systemcomprising: a scanner, configured to produce x-ray projection data as anobject is passed through the scanner, at least a portion of the scannerbeing received within a structure, the structure having an input openingand an outlet opening, the input opening being configured to receiveobjects to be scanned and the outlet opening being configured to receiveobjects scanned by the scanner; an input conveyor for passing aplurality of bins through the input opening to the outlet opening, theinput conveyor having an input end for receiving the plurality of binsto pass the plurality of bins into the input opening and an output endfor delivering the plurality of bins from the outlet opening; a returnconveyor positioned to return the plurality of bins to an area proximateto the input end of the input conveyor, the return conveyor beingpositioned below the input conveyor, wherein the return conveyor doesnot pass through the scanner; and a sensor positioned with respect tothe return conveyor, the sensor configured to sense a bin on the returnconveyor.
 2. The security screening system as in claim 1, wherein thereturn conveyor extends past the input end and the output end of theinput conveyor.
 3. The security screening system as in claim 1, whereinthe return conveyor is driven by a motor and the return conveyor has aninput end proximate to the output end of the input conveyor and anoutput end proximate to the input end of the input conveyor, wherein thesensor is positioned to detect the presence of one of the plurality ofbins at the output end of the return conveyor, wherein the sensorprovides a stop signal to the motor when the presence of one of theplurality of bins is detected at the output end of the return conveyorand the sensor provides a start signal to the motor when the presence ofone of the plurality of bins is not detected at the output end.
 4. Thesecurity screening system as in claim 3, wherein the return conveyorextends past the input end and the output end of the input conveyor. 5.The security screening system as in claim 3, wherein the input end ofthe return conveyor is below the input conveyor and the input end of thereturn conveyor is fed by a plurality of rollers arranged to define adownwardly inclined path from the output end of the input conveyor tothe input end of the return conveyor.
 6. The security screening systemas in claim 5, wherein the return conveyor comprises an upwardlyinclined portion ending at the output end of the return conveyor.
 7. Thesecurity screening system as in claim 1, further comprising a platformpositioned to receive at least one of the plurality of bins from anoutput end of the return conveyor, wherein the return conveyor is drivenby a motor and the sensor is positioned to detect the presence of one ofthe plurality of bins on the platform, wherein the sensor provides astop signal to the motor when the presence of one of the plurality ofbins is detected on the platform and the sensor provides a start signalto the motor when the presence of one of the plurality of bins is notdetected on the platform.
 8. The security screening system as in claim7, wherein the platform extends past the input end of the inputconveyor.
 9. The security screening system as in claim 1, wherein eachof the plurality of bins comprises a peripheral wall and a bottom,wherein the peripheral wall and the bottom define a receiving area, anda forward portion and a rearward portion of the peripheral wall comprisean x-ray inhibiting material, wherein the forward portion and therearward portion are each configured to substantially occupy the inputopening or the outlet opening of the structure when either the forwardportion or the rearward portion pass through the input opening and theoutlet opening of the structure, wherein the forward portion andrearward portion prevent x-rays from exiting the structure througheither the input opening or the outlet opening of the structure.
 10. Thesecurity screening system as in claim 9, wherein the peripheral wallfurther comprises a pair of side walls each extending between theforward portion and the rearward portion, the pair of side walls eachhaving an exterior surface and an interior surface; an indicatordisposed on the exterior surface of one of the pair of side walls andthe x-ray inhibiting material is lead integrally molded into the forwardportion and the rearward portion; and the security screening systemfurther comprises a scanner configured to detect the presence of theindicator of one of the plurality of bins, wherein the indicator and thescanner are located to provide a signal when one of the plurality ofbins is located proximate to either the input opening or the outletopening of the structure and the x-ray inhibiting material of the bin isdisposed within either the input opening or the outlet opening of thestructure and the scanner is prevented from producing the x-rayprojection data unless the signal is generated.
 11. The securityscreening system as in claim 9, wherein the forward portion and therearward portion of the peripheral wall are each configured to provide apredetermined distance between an object disposed in the receiving areaand the x-ray inhibiting material of either the forward portion and therearward portion of the peripheral wall.
 12. The system as in claim 9,wherein each of the plurality of bins are substantially uniform in sizeand configuration and the scanner is a spiral computed tomographyscanner having an x-ray source and a detector array rotatably mounted toa gantry of the spiral computed tomography scanner and the systemfurther comprises a plurality of rollers positioned at the input end andthe output end of the input conveyor.
 13. The system as in claim 1,wherein the return conveyor is positioned directly below the inputconveyor and wherein the return conveyor does not increase an overalldimension of the system.
 14. A security screening system for scanningitems, the system comprising: a scanner, configured to produce x-rayprojection data as an object is passed through the scanner, at least aportion of the scanner being received within a structure, the structurehaving an input opening and an outlet opening, the input opening beingconfigured to receive objects to be scanned and the outlet opening beingconfigured to receive objects scanned by the scanner; an input conveyorfor passing a plurality of bins through the input opening to the outletopening, the input conveyor having an input end for receiving theplurality of bins to pass the plurality of bins into the input openingand an output end for delivering the plurality of bins from the outletopening; a return pathway positioned to return the plurality of bins toan area proximate to the input end of the input conveyor, the returnpathway being positioned below the input conveyor, wherein the returnpathway does not pass through the scanner; and a sensor positioned withrespect to the return conveyor, the sensor configured to sense a bin onthe return conveyor.
 15. The security screening system as in claim 14,wherein the return pathway extends past the input end and the output endof the input conveyor and the security screening system is part of anairport security check point.
 16. The security screening system as inclaim 15, wherein the return pathway is comprises a plurality of rollersand a portion of the return pathway is inclined downwardly away from theoutput end of the input conveyor, wherein the return conveyor furthercomprises a bumper positioned proximate to the input end of the inputconveyor, wherein the bumper prevents the plurality of bins from rollingoff an end of the return pathway.
 17. The security screening system asin claim 14, wherein the return pathway is positioned directly below theinput conveyor and wherein the return pathway does not increase anoverall dimension of the system.
 18. The security screening system as inclaim 14, wherein each of the plurality of bins comprises a peripheralwall and a bottom, wherein the peripheral wall and the bottom define areceiving area, and a forward portion and a rearward portion of theperipheral wall comprise an x-ray inhibiting material, wherein theforward portion and the rearward portion are each configured tosubstantially occupy the input opening or the outlet opening of thestructure when either the forward portion or the rearward portion passthrough the input opening and the outlet opening of the structure,wherein the forward portion and rearward portion prevent x-rays fromexiting the structure through either the input opening or the outletopening of the structure.
 19. The security screening system as in claim18, wherein the peripheral wall further comprises a pair of side wallseach extending between the forward portion and the rearward portion, thepair of side walls each having an exterior surface and an interiorsurface; an indicator disposed on the exterior surface of one of thepair of side walls and the x-ray inhibiting material is lead integrallymolded into the forward portion and the rearward portion; and thesecurity screening system further comprises a scanner configured todetect the presence of the indicator of one of the plurality of bins,wherein the indicator and the scanner are located to provide a signalwhen one of the plurality of bins is located proximate to either theinput opening or the outlet opening of the structure and the x-rayinhibiting material of the bin is disposed within either the inputopening or the outlet opening of the structure and the scanner isprevented from producing the x-ray projection data unless the signal isgenerated.
 20. The security screening system as in claim 18, wherein theforward portion and the rearward portion of the peripheral wall are eachconfigured to provide a predetermined distance between an objectdisposed in the receiving area and the x-ray inhibiting material ofeither the forward portion and the rearward portion of the peripheralwall.
 21. A method for returning a plurality of empty bins used in asecurity screening process, the method comprising: advancing a pluralityof bins through a scanner using an input conveyor, the input conveyorhaving an input end for receiving the plurality of bins and an outputend for delivering the plurality of bins, the scanner being configuredto produce x-ray projection data as an object is passed through thescanner, at least a portion of the scanner being received within astructure, the structure having an input opening and an outlet opening,the input opening being configured to receive objects to be scanned andthe outlet opening being configured to receive objects scanned by thescanner; and returning the plurality of bins to the input end after theyhave passed through the scanner with a return conveyor, the returnconveyor being configured to return the plurality of bins to an areaproximate to the input end of the input conveyor, the return conveyorbeing positioned below the input conveyor without passing through thescanner, and the return conveyor including a sensor positioned withrespect to the return conveyor, the sensor configured to sense a bin onthe return conveyor.
 22. The method as in claim 21, wherein the returnconveyor is driven by a motor and the return conveyor has an input endproximate to the output end of the input conveyor and an output endproximate to the input end of the input conveyor, wherein the sensor ispositioned to detect the presence of one of the plurality of bins at theoutput end of the return conveyor, wherein the sensor provides a stopsignal to the motor when the presence of one of the plurality of bins isdetected at the output end of the return conveyor and the sensorprovides a start signal to the motor when the presence of one of theplurality of bins is not detected at the output end.